By Yoo Cheong-mo SEOUL, April 9 (Yonhap) -- South Korea's ruling party is forecast to win a majority in general elections Wednesday, bolstering conservative President Lee Myung-bak's bid to carry out sweeping economic reforms and get tougher on nuclear-armed North Korea, exit polls showed.

According to exit polls by broadcasters KBS and MBC, the ruling Grand National Party (GNP) is expected to secure between 154 and 178 seats in the 299-seat unicameral National Assembly, while the main opposition United Democratic Party (UDP) is forecast to garner between 67 and 89 seats.

A separate prediction by SBS television put the number of seats to be won by the GNP at between 162 and 181, compared with 68 to 85 seats for the UDP, while cable television broadcaster YTN forecast the ruling party would capture between 160 and 184 seats.

GNP leadership has said the party needs to secure at least 170 seats to push through various business-friendly reforms, as some of Lee's reform programs, including the controversial waterway project, are opposed by the party's largest faction led by Lee's political foe and former GNP chairwoman Park Geun-hye and her followers, totaling about 25 or so.

Lee won a landslide victory in December's presidential election, ending a decade of liberal rule by his two predecessors. Lee and his party have vowed to take a tougher stance toward communist North Korea after a 10-year "sunshine" engagement policy pursued by the two liberal presidents.

Meanwhile, former GNP presidential candidate Lee Hoi-chang's Liberty Forward Party is expected to win between 10 and 18 seats, failing to secure the 20 seats necessary for the minor party to form a parliamentary negotiating body which is guaranteed various favors and benefits in terms of parliamentary influence and state subsidies.

According to the TV exit polls, the liberal minority Democratic Labor Party is forecast to win between two and six seats, while independent candidates are expected to take a maximum of 26 seats.

The predictions are based on the combination of the results of exit polls and surveys made before the vote. Official electoral results are due at around midnight Thursday.

Voting ended at 6:00 p.m. at over 13,000 polling stations across the country.

Up for grabs are 245 directly contested seats and an additional 54 seats to be allotted according to the votes each party gets under the proportional representation system.

The turnout is expected to fall to a record low of below 50 percent, illustrating voter frustration over extended political wrangling between the rival parties.

The UDP currently holds 136 seats in the outgoing Assembly, while the GNP has 112.

Analysts said a solid GNP victory would help the parliamentary endorsement of Lee's various economic reform bills and programs, including the construction of inland waterways across the peninsula and the ratification of a free trade agreement with the U.S.